Open AccessRecording Temporal Signals with Minutes Resolution Using Enzymatic DNA Synthesis
Author(s) -
Namita Bhan,
Alec Callisto,
Jonathan Strutz,
Joshua I. Glaser,
Reza Kalhor,
Edward S. Boyden,
George M. Church,
Konrad Kording,
Keith E.J. Tyo
Publication year - 2021
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.1c07331
Subject(s) - terminal deoxynucleotidyl transferase , chemistry , dna , encode , nucleotide , biophysics , dna polymerase , a dna , resolution (logic) , biological system , computational biology , biochemistry , computer science , gene , biology , tunel assay , apoptosis , artificial intelligence
Employing DNA as a high-density data storage medium has paved the way for next-generation digital storage and biosensing technologies. However, the multipart architecture of current DNA-based recording techniques renders them inherently slow and incapable of recording fluctuating signals with subhour frequencies. To address this limitation, we developed a simplified system employing a single enzyme, terminal deoxynucleotidyl transferase (TdT), to transduce environmental signals into DNA. TdT adds nucleotides to the 3'-ends of single-stranded DNA (ssDNA) in a template-independent manner, selecting bases according to inherent preferences and environmental conditions. By characterizing TdT nucleotide selectivity under different conditions, we show that TdT can encode various physiologically relevant signals such as Co 2+ , Ca 2+ , and Zn 2+ concentrations and temperature changes in vitro . Further, by considering the average rate of nucleotide incorporation, we show that the resulting ssDNA functions as a molecular ticker tape. With this method we accurately encode a temporal record of fluctuations in Co 2+ concentration to within 1 min over a 60 min period. Finally, we engineer TdT to allosterically turn off in the presence of a physiologically relevant concentration of calcium. We use this engineered TdT in concert with a reference TdT to develop a two-polymerase system capable of recording a single-step change in the Ca 2+ signal to within 1 min over a 60 min period. This work expands the repertoire of DNA-based recording techniques by developing a novel DNA synthesis-based system that can record temporal environmental signals into DNA with a resolution of minutes.